三门峡虢国墓地M2009出土铁刃铜器的科学分析及其相关问题

三门峡虢国墓地出土铁刃铜器是中原地区较早的用铁证据。利用金相显微镜、扫描电子显微镜-能谱仪（SEM-EDS）、电子探针（EPMA）等多种方法，对三门峡虢国墓地M2009出土的3件铁刃铜器进行了科学检测分析。结果显示，铜骹铁叶矛（STG001）铁质部分可见硅酸盐与氧化亚铁共生夹杂，且沿着加工方向拉长，其材质为块炼铁。铁刃铜削（SGT002）和铜内铁援戈（SGT003）残留铁金属颗粒中均检测出较为显著的Ni和少量Co，SEM-EDS线扫描分析显示Ni和Co在各相之间存在高低交错的分布特征，判断其材质为陨铁，其Ni含量处于铁陨石ⅢC和ⅢD之间，原始结构应属极细粒八面体铁陨石（Off）或无纹铁陨石（Ataxite）类型。样品STG001和SGT002铜质部分均保留较为典型的锡青铜铸造组织形态，基体为已腐蚀的α固溶体，残余（α+δ）固溶体均匀分布，铜铁结合处无明显的晶粒变形和再结晶现象，显示该区域未经历铸后的冷热加工。由此推断，铁刃部分应是先锻打加工成形后，嵌入铸造铜质部分的组合陶范，通过铸接的方式与铜质部分紧密结合而形成铜铁复合器物。简要梳理了中国早期铁金属的使用证据，指出陨铁和人工冶铁制品在虢国墓地的同时出现，显示了该时期在研究中国铁冶金技术起源和传播中的重要地位。西北地区在早期块炼铁技术传播中扮演了重要角色，而生铁技术在中原地区的产生则与商周青铜铸造技术传统关系密切。

Scientific Research of Bimetallic Objects Unearthed from M2009 in the Guo State Cemetery at Sanmenxia

The bronze-iron bimetallic objects unearthed from the Guo State Cemetery in Sanmenxia City are evidences of early use of iron in China’s Central Plains areas. This paper carries out scientific analyses of 3 bimetallic objects from tomb No. 2009 of this cemetery using metallography microscopy, Scanning Electronic Microscope-Energy Dispersive X-ray Spectroscopy (SEM-EDS) and Electron Microprobe (EMPA). It is revealed that the iron blade of spear head (STG001) was made of bloomery iron. Multiple-phased inclusions of silicate and iron oxide were elongated during the manufacturing process and arrayed along the deformation directions. Residue iron pills in the knife (SGT002) and the Ge Blade (SGT003) were found to be content notable Ni and a few of Co, and the result of line scanning analyses by the SEM-EDS shows interval distribution of nickel among different phase, indicating the meteoritic origin of the iron metal used to make the blades. The original Ni content of the meteoritic iron would fall in the ranges of IIIC and IIID types which will give the meteorites a microstructure of Finest (Off) or Ataxite. Metallography of bronze part of samples SGT001 and SGT 002 were observed to be typical as-casting microstructure of tin bronze with corroded α solid solution matrix and dispersed particles of (α+δ) eutectoid. The fact that there is no sign of deformation and recrystallization at the interface of iron and bronze parts indicates no further mechanical processing had been applied in the joint region. It is then inferred that the pre-made iron blades by were embedded into the casing mould and connected with bronze part by a cast-on process. On the basis of analytical results, this paper also briefly reviews the early use of iron metal in China and points out that the co-occurrence of meteoritic and manmade iron in the Guo State Cemetery demonstrated that this period had been a crucial stage in the development of iron metallurgy in China. The Northwest Region of China had played an important role during the transmission of early bloomery iron metallurgy while the establishment of cast iron technology in China’s Central Plains area would have a close relationship with the pre-existed technological tradition of bronze casting during the Shang and Zhou Periods.